Data Sheet Rev. 1.03 / November 2014 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner Mobile Sensing ICs Smart and Mobile ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Brief Description Benefits The measured and corrected sensor values are provided at the digital output pins, which can be 2 configured as I C™* (≤ 3.4MHz) or SPI (≤ 20MHz). Digital compensation of signal offset, sensitivity, temperature, and non-linearity is accomplished via a 26-bit internal digital signal processor (DSP) running a correction algorithm. Calibration coefficients are stored on-chip in a highly reliable, non-volatile, multiple-time programmable (MTP) memory. Programming the ZSSC3218 is simple via the serial interface. The interface is used for the PC-controlled calibration procedure, which programs the set of calibration coefficients in memory. The ZSSC3218 provides accelerated signal processing, increased resolution, and improved noise immunity in order to support high-speed control, safety, and real-time sensing applications with the highest requirements for energy efficiency. Features Flexible, programmable analog front-end design; up to 18-bit analog-to-digital converter (ADC) Fully programmable gain amplifier for optimizing sensor signals: gain range 6.6 to 216 (linear) Internal auto-compensated temperature sensor Digital compensation of individual sensor offset; st nd 1 and 2 order digital compensation of sensor st nd gain as well as 1 and 2 order temperature gain and offset drift Programmable interrupt operation High-speed sensing: e.g. 16-bit conditioned -1 sensor signal measurement rate >500s Typical sensor elements can achieve an accuracy of better than ±0.10% FSO** at -40 to 85°C Integrated 26-bit calibration math digital signal processor (DSP) Fully corrected signal at digital output Layout customized for die-die bonding with sensor for high-density chip-on-board assembly One-pass calibration minimizes calibration costs No external trimming, filter, or buffering components required Highly integrated CMOS design Integrated reprogrammable non-volatile memory Excellent for low-voltage and low-power battery applications Optimized for operation in calibrated resistive (e.g., pressure) sensor or calibrated absolute voltage (e.g., thermopile) sensor modules Physical Characteristics Supply voltage range: 1.68V to 3.6V Current consumption: 1.0mA (operating mode) Sleep State current: 20nA (typical) Temperature resolution: <0.003K/LSB Best-in-class energy-efficiency: with 16-bit resolution: <140pJ/step with 18-bit resolution: <50pJ/step Operation temperature: –40°C to +85°C Small die size Delivery options: die for wafer bonding * I2C™ is a trademark of NXP. ** FSO = Full Scale Output. ZSSC3218 Application Example VSS VDD VDD ry Batte Stacked-Die Sensor Module VDD VSS ZSSC3218 VDDB RES MISO INP(+) SS RES VDDB EOC SS VSS sensor element INP INN VSSB EOC MOSI SDA INN(-) VSSB MOSI SDA SCLK SCL Microcontroller Signal Output / Post-processing The ZSSC3218 is a sensor signal conditioner (SSC) integrated circuit for high-accuracy amplification and analog-to-digital conversion of a differential or pseudo-differential input signal. Designed for highresolution sensor module applications, the st nd ZSSC3218 can perform offset, span, and 1 and 2 order temperature compensation of the measured signal. Developed for correction of resistive bridge or absolute voltage sensors, it can also provide a corrected temperature output measured with an internal sensor. MISO SCLK SCL For more information, contact ZMDI via [email protected]. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 — November 17, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC VDDB ZSSC3218 Block Diagram VTP VTN Vreg int Temperature Reference Sensor VDD AGND / CM Generator Bias Current Generator Power Ctr. Voltage Regulator VSS Sensor Bridge INP INN Multiplexer ZSSC3218 A PreAmplifier D DSP Core (Calculations, Communication) 18 Bit VSSB SPI Power-ON Reset Clock Generator Applications Barometric altitude measurement for portable navigation or emergency call systems Altitude measurement for car navigation Weather forecast Fan control Industrial, pneumatic, and liquid pressure High-resolution temperature measurements Object-temperature radiation (via thermopile) Oscillator System Control Unit MTP I²CTM Sales Code Description Package ZSSC3218BI1B Die—temperature range: –40°C to +85 °C; thickness 304µm Unsawn wafer ZSSC3218BI2B Die—temperature range: –40°C to +85 °C; thickness 725µm (w/o backlapping) Unsawn wafer ZSSC3218BI1D ES Die—temperature range: –40°C to +85 °C; thickness 304µm, engineering samples Sawn die in waffle pack ZSSC3218BI3R ES PQFN24—temperature range: –40°C to +85 °C; engineering samples Packaged die Sales and Further Information www.zmdi.com EOC SCLK/SCL SS MOSI/SDA MISO RES [email protected] Zentrum Mikroelektronik Dresden AG Global Headquarters Grenzstrasse 28 01109 Dresden, Germany ZMD America, Inc. 1525 McCarthy Blvd., #212 Milpitas, CA 95035-7453 USA Central Office: Phone +49.351.8822.306 Fax +49.351.8822.337 USA Phone 1.855.275.9634 Phone +1.408.883.6310 Fax +1.408.883.6358 European Technical Support Phone +49.351.8822.7.772 Fax +49.351.8822.87.772 DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer, licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or otherwise. European Sales (Stuttgart) Phone +49.711.674517.55 Fax +49.711.674517.87955 Zentrum Mikroelektronik Dresden AG, Japan Office 2nd Floor, Shinbashi Tokyu Bldg. 4-21-3, Shinbashi, Minato-ku Tokyo, 105-0004 Japan ZMD FAR EAST, Ltd. 3F, No. 51, Sec. 2, Keelung Road 11052 Taipei Taiwan Phone +81.3.6895.7410 Fax +81.3.6895.7301 Phone +886.2.2377.8189 Fax +886.2.2377.8199 Zentrum Mikroelektronik Dresden AG, Korea Office U-space 1 Building 11th Floor, Unit JA-1102 670 Sampyeong-dong Bundang-gu, Seongnam-si Gyeonggi-do, 463-400 Korea Phone +82.31.950.7679 Fax +82.504.841.3026 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03— November 17, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Table of Contents 1 2 IC Characteristics .......................................................................................................................................... 7 1.1. Absolute Maximum Ratings .................................................................................................................... 7 1.2. Operating Conditions .............................................................................................................................. 7 1.3. Electrical Parameters ............................................................................................................................. 8 1.4. Power Supply Rejection Ratio (PSRR) vs. Frequency ......................................................................... 10 Circuit Description ....................................................................................................................................... 11 2.1. Brief Description ................................................................................................................................... 11 2.2. Signal Flow and Block Diagram ............................................................................................................ 11 2.3. Analog Front End .................................................................................................................................. 12 2.3.1. Amplifier ......................................................................................................................................... 12 2.3.2. Analog-to-Digital Converter ............................................................................................................ 14 2.3.3. Selection of Gain and Offset – Sensor System Dimensioning ...................................................... 16 2.3.4. Temperature Measurement ........................................................................................................... 17 2.3.5. External Sensor Supply: Bridge Sensors ....................................................................................... 17 2.3.6. External Sensor: Absolute Voltage Source Sensors ..................................................................... 17 2.4. 3 Digital Section ....................................................................................................................................... 18 2.4.1. Digital Signal Processor (DSP) Core ............................................................................................. 18 2.4.2. MTP Memory.................................................................................................................................. 18 2.4.3. Clock Generator ............................................................................................................................. 18 2.4.4. Power Supervision ......................................................................................................................... 18 2.4.5. Interface ......................................................................................................................................... 18 Functional Description ................................................................................................................................. 19 3.1. Power Up .............................................................................................................................................. 19 3.2. Measurements ...................................................................................................................................... 19 3.3. Interrupt (EOC Pin) ............................................................................................................................... 20 3.4. Operational Modes ............................................................................................................................... 22 3.4.1. 3.5. 2 SPI/I C™ Commands .................................................................................................................... 25 Communication Interface ...................................................................................................................... 28 3.5.1. Common Functionality ................................................................................................................... 28 3.5.2. SPI.................................................................................................................................................. 29 3.5.3. I C™ ............................................................................................................................................... 31 3.6. 2 Multiple Time Programmable (MTP) Memory ...................................................................................... 33 3.6.1. Programming Memory.................................................................................................................... 33 3.6.2. Memory Contents ........................................................................................................................... 34 Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 4 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.7. Calibration Sequence ........................................................................................................................... 43 3.7.1. Calibration Step 1 – Assigning Unique Identification ..................................................................... 43 3.7.2. Calibration Step 2 – Data Collection .............................................................................................. 44 3.7.3. Calibration Step 3a) – Coefficient Calculations ............................................................................. 45 3.7.4. Calibration Step 3b) – Post-Calibration Offset Correction ............................................................. 45 3.7.5. SSC Measurements ....................................................................................................................... 45 3.8. The Calibration Math ............................................................................................................................ 46 3.8.1. Bridge Signal Compensation ......................................................................................................... 46 3.8.2. Temperature Signal Compensation ............................................................................................... 49 3.8.3. Measurement Output Data Format ................................................................................................ 50 4 Package Information and Pad Assignments ............................................................................................... 51 5 Quality and Reliability .................................................................................................................................. 55 6 Ordering Sales Codes ................................................................................................................................. 55 7 Related Documents ..................................................................................................................................... 55 8 Glossary ...................................................................................................................................................... 56 9 Document Revision History ......................................................................................................................... 57 Table of Figures Figure 2.1 ZSSC3218 Functional Block Diagram, Resistive-Bridge Sensor .................................................. 11 Figure 2.2 ZSSC3218 Functional Block Diagram, Voltage-Source Sensor .................................................... 12 Figure 2.3 Gain and Offset Setup ................................................................................................................... 17 Figure 3.1 Interrupt Functionality .................................................................................................................... 21 Figure 3.2 Operational Flow Chart: Power Up ................................................................................................ 23 Figure 3.3 Operational Flow Chart: Command Mode and Normal Mode (Sleep and Cyclic) ......................... 24 Figure 3.4 SPI Configuration CPHA=0............................................................................................................ 29 Figure 3.5 SPI Configuration CPHA=1............................................................................................................ 30 Figure 3.6 SPI Command Request ................................................................................................................. 30 Figure 3.7 SPI Read Status ............................................................................................................................ 31 Figure 3.8 SPI Read Data ............................................................................................................................... 31 Figure 3.9 I2C™ Command Request .............................................................................................................. 32 2 Figure 3.10 I C™ Read Status .......................................................................................................................... 32 2 Figure 3.11 I C™ Read Data ............................................................................................................................ 32 Figure 4.1 ZSSC3218 Pad Placement ............................................................................................................ 51 Figure 4.2 General PQFN24 Package Dimensions ........................................................................................ 53 Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 5 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC List of Tables Table 1.1 Maximum Ratings ............................................................................................................................ 7 Table 1.2 Operating Conditions ....................................................................................................................... 7 Table 1.3 Requirements for VDD Power-on Reset .......................................................................................... 8 Table 1.4 Electrical Parameters ....................................................................................................................... 8 Table 2.1 Amplifier Gain: Stage 1 .................................................................................................................. 13 Table 2.2 Amplifier Gain: Stage 2 .................................................................................................................. 13 Table 2.3 Gain Polarity .................................................................................................................................. 13 Table 2.4 ADC Conversion Times for a Single Analog-to-Digital Conversion ............................................... 14 Table 2.5 ADC Offset Shift............................................................................................................................. 15 Table 2.6 Typical Conversion Times vs. Noise Performance with Full Sensor Signal Conditioning for AZSM, SM, AZTM, and TM (Bridge-Type Sensor) .................................................................................... 15 Table 3.1 SPI/I C™ Commands .................................................................................................................... 25 Table 3.2 Get_Raw Commands .................................................................................................................... 27 Table 3.3 General Status Byte ....................................................................................................................... 28 Table 3.4 Mode Status ................................................................................................................................... 29 Table 3.5 MTP Memory Content Assignments .............................................................................................. 34 Table 3.6 Measurement Results of ADC Raw Measurement Request (two’s complement) ......................... 50 Table 3.7 Calibration Coefficients (Factors and Summands) in Memory (sign-magnitude) .......................... 50 Table 3.8 Output Results from SSC-Correction Math or DSP—Sensor and Temperature ........................... 50 Table 3.9 Interrupt Thresholds TRSH1 and TRSH2—Format as for SSC-Correction Math Output ............. 50 Table 4.1 Pad Assignments ........................................................................................................................... 52 Table 4.2 Die Connection and Bond Parameter ............................................................................................ 52 Table 4.3 Physical Package Dimensions ....................................................................................................... 53 Table 4.4 Pin Assignments PQFN24 ............................................................................................................. 54 2 Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 6 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 1 IC Characteristics 1.1. Absolute Maximum Ratings Note: The absolute maximum ratings are stress ratings only. The ZSSC3218 might not function or be operable above the recommended operating conditions. Stresses exceeding the absolute maximum ratings might also damage the device. In addition, extended exposure to stresses above the recommended operating conditions might affect device reliability. ZMDI does not recommend designing to the “Absolute Maximum Ratings.” Table 1.1 Maximum Ratings PARAMETER SYMBOL Min Voltage Reference VSS Analog Supply Voltage Voltage at all Analog and Digital IO Pins Input Current into any Pin except RES, SS 1), 2) Electrostatic Discharge Tolerance – Human Body Model (HBM1) Storage Temperature 3) TYP MAX UNITS 0 0 V VDD -0.4 3.63 V VA_IO, VD_IO -0.5 VDD+0.5 V IIN -100 100 mA VHBM1 ±4000 - V TSTOR -50 125 °C 1) Latch-up current limit for RES, ZMDI-test and SS: ±70mA. 2) Latch-up resistance; reference for pin is 0V. 3) HBM1: C = 100pF charged to VHBM1 with resistor R = 1.5k in series based on MIL 883, Method 3015.7. ESD protection referenced to the Human Body Model is tested with devices in ceramic dual in-line packages (CDIP) during product qualification. 1.2. Operating Conditions The reference for all voltages is Vss. Table 1.2 Operating Conditions PARAMETER SYMBOL MIN TYP MAX UNIT Supply Voltage VDD 1.68 - 3.6 V VDD Rise Time tVDD 200 μs Bridge Current 1.8 1) IVDDB Operation Temperature Range External (Parasitic) Capacitance between VDDB and VSS 1) mA 16.5 TAMB -40 CL 0.01 - 85 °C 50 nF Power supply rejection is reduced if a current in the range of 16.5mA > IVDDB > 1.8mA is drawn out of VDDB. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 7 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC A dynamic power-on-reset circuit is implemented in order to achieve minimum current consumption in idle mode. The VDD low level and the subsequent rise time and VDD rising slope must meet the requirements in Table 1.1 to guarantee an overall IC reset; lower VDD low levels allow slower rising of the subsequent on-ramp of VDD. Other combinations might also be possible. For example, the reset trigger can be influenced by increasing the power-down time and lowering the VDD rising slope requirement. Alternatively, the RES pin can be connected and used to control safe resetting of the ZSSC3218. RES is active-low; a VDD-VSS-VDD transition at the RES pin leads to a complete IC reset. Table 1.3 Requirements for VDD Power-on Reset PARAMETER SYMBOL MIN TYP MAX UNIT tSPIKE 3 - - µs VDD Low Level VDDlow 0 - 0.2 V VDD Rising Slope SRVDD 10 - - V/ms Power Down Time (duration of VDD Low Level) 1.3. Electrical Parameters All parameter values are valid only under the specified operating conditions. All voltages are referenced to Vss. Table 1.4 Electrical Parameters Note: See important table notes at the end of the table. Parameter Symbol Conditions/Comments Min Typ Max Unit 1.60 1.68 1.75 V 1050 1500 µA 20 250 nA Supply External Sensor Supply Voltage, ADC Reference Voltage VDDB Current Consumption IVDD Internally generated Active State, average Power Supply Rejection 20·log10(VDD/VDDB) (see section 1.4) Sleep State, idle current, 85°C VDD = 1.8V 17 60 88 dB VDD = 2V 32 65 91 dB 18 Bit 1.1 MHz 1.1 kHz 2.3 kHz PSRVDD Analog-to-Digital Converter (ADC, A2D) Resolution rADC ADC Clock Frequency fADC Internal ADC clock fS,raw Conversions per second for single 18-bit external sensor A2D conversion (w/o AZ) Conversions per second for single 16-bit temperature sensor A2D conversion (w/o AZ) Conversion Rate Data Sheet November 17, 2014. 12 0.9 1 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 8 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Parameter Symbol Conditions/Comments Min Typ Max Unit Amplifier Gain Gamp 64 steps 6.6 Gain Error Gerr Referenced to nominal gain -2.5 216 - 2.5 % 0.01 %FSO 300 Hz 1.05 V 50 kΩ 999 Ω Sensor Signal Conditioning Performance IC Accuracy Error 1) ErrA,IC Conversion Rate, 18-Bit SSC fS, SSC Accuracy error for sensor that is ideally linear (in temperature and measurand) Conversion per second for fully corrected 18-bit measurement 270 Input Input Voltage Range External Sensor Bridge Resistance VINP, VINN Input voltage range at INP and INN RBR Full power supply disturbance rejection (PSRR) capabilities Reduced PSRR, but full functionality 0.65 1 10 100 Power-Up tSTA1 VDD ramp up to interface communication (see section 3.1) 1 ms tSTA2 VDD ramp up to analog operation 2.5 ms tWUP1 Sleep to Active State interface communication 0.5 ms tWUP2 Sleep to Active State analog operation 2 ms 4.4 MHz Start-up Time Wake-up Time Oscillator Internal Oscillator Frequency fCLK 3.6 4 Internal Temperature Sensor Temperature Resolution -40°C to +85°C 0.003 K/LSB Interface and Memory Maximum capacitance at MISO line: 40pF at VDD=1.8V SPI Clock Frequency fC,SPI I²C™ Clock Frequency fC,I2C Program Time tprog MTP programming time per 16-bit register Endurance nMTP Number of reprogramming cycles Data Retention tRET_MTP 1000h at 125°C 1) 1 5 1000 10000 10 20 MHz 3.4 MHz 16 ms numeric a Percentage referred to maximum full-scale output (FSO); e.g. for 18-bit measurements: ErrA,IC [%FSO] = 100 · MAX{ | ADCmeas – ADCideal | } / 218. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 9 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 1.4. Power Supply Rejection Ratio (PSRR) vs. Frequency Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 10 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 2 Circuit Description 2.1. Brief Description The ZSSC3218 provides a highly accurate amplification of bridge sensor signals. The compensation of sensor offset, sensitivity, temperature drift, and non-linearity is accomplished via a 26-bit DSP core running a correction algorithm with calibration coefficients stored in a non-volatile memory. The ZSSC3218 can be configured for a wide range of resistive bridge sensor types and for absolute voltage source sensors. A digital interface (SPI or 2 I C™) enables communication. The ZSSC3218 supports two operational modes: Normal Mode and Command Mode. Normal Mode is the standard operating mode. Typically in Normal Mode, the ZSSC3218 wakes up from a Sleep State (low power), runs a measurement in Active State, and automatically returns to the Sleep State. (See section 3.4 for details on operational modes.) 2.2. Signal Flow and Block Diagram See Figure 2.1 and Figure 2.2 for the ZSSC3218 block diagram for different input sensors. The sensor bridge supply VDDB and the power supply for analog circuitry are provided by a voltage regulator, which is optimized for power supply disturbance rejection (PSRR). See section 1.4 for a graph of PSRR versus frequency. To improve noise suppression, the digital blocks are powered by a separate voltage regulator. A power supervision circuit monitors all supply voltages and generates appropriate reset signals for initializing the digital blocks. The System Control Unit controls the analog circuitry to perform the three measurement types: external sensor, temperature, and offset measurement. The multiplexer selects the signal input to the amplifier, which can be the external signals from the input pins INP and INN or the internal temperature reference sensor signals. A full measurement request will trigger an automatic sequence of all measurement types and all input signals. Figure 2.1 ZSSC3218 Functional Block Diagram, Resistive-Bridge Sensor VDDB VTP VTN Vreg int Temperature Reference Sensor VDD AGND / CM Generator Bias Current Generator Power Ctr. Voltage Regulator VSS Sensor Bridge INP INN Multiplexer ZSSC3218 A PreAmplifier D DSP Core (Calculations, Communication) 18 Bit VSSB SPI Power-ON Reset Data Sheet November 17, 2014. Clock Generator Oscillator EOC System Control Unit MTP I²CTM © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. SCLK/SCL SS MOSI/SDA MISO RES 11 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 2.2 ZSSC3218 Functional Block Diagram, Voltage-Source Sensor VDDB VTP VTN Vreg int Temperature Reference Sensor VDD AGND / CM Generator Bias Current Generator Power Ctr. Voltage Regulator VSS Multiplexer V source ZSSC3218 INP INN A PreAmplifier D DSP Core (Calculations, Communication) 18-Bit VSSB SPI Power-On Reset (POR) Clock Generator Oscillator EOC System Control Unit MTP I²CTM SCLK/SCL SS MOSI/SDA MISO RES The amplifier consists of two stages with programmable gain values. The ZSSC3218 employs a programmable analog-to-digital converter (ADC) optimized for conversion speed and noise suppression. The programmable resolution from 12 to 18 bits provides flexibility for adapting the conversion characteristics. To improve power supply noise suppression, the ADC uses the bridge supply VDDB as its reference voltage leading to a ratiometric measurement topology if the external sensor is a bridge-type element. The remaining IC-internal offset and the sensor element offset, i.e., the overall system offset for the amplifier and ADC, can be canceled by means of an offset and auto-zero measurement, respectively. st nd The DSP accomplishes the auto-zero, span, and 1 and 2 order temperature compensation of the measured external sensor signal. The correction coefficients are stored in the MTP memory. 2 The ZSSC3218 supports SPI and I C™ interface communication for controlling the ZSSC3218, configuration, and measurement result output. 2.3. Analog Front End 2.3.1. Amplifier The amplifier has a fully differential architecture and consists of two stages. The amplification of each stage and the external sensor gain polarity are programmable via settings in the Measurement Configuration Register SM_config1 and SM_config2 (addresses 12HEX and 16HEX; see section 3.6.2) in the MTP memory (for details, see section 2.4.2). Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 12 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC * The first 6 bits of SM_config are the programmable gain settings Gain_stage1 and Gain_stage2. The options for the programmable gain settings are listed in Table 2.1 and Table 2.2. Table 2.1 Amplifier Gain: Stage 1 Gain_stage1 SM_config Bit G2 SM_config Bit G1 SM_config Bit G0 Gainamp1 0 0 0 6 0 0 1 12 0 1 0 20 0 1 1 30 1 0 0 40 1 0 1 60 1 1 0 80 1 1 1 120 Table 2.2 Amplifier Gain: Stage 2 Gain_stage2 SM_config Bit G5 SM_config Bit G4 SM_config Bit G3 Gainamp2 0 0 0 1.1 0 0 1 1.2 0 1 0 1.3 0 1 1 1.4 1 0 0 1.5 1 0 1 1.6 1 1 0 1.7 1 1 1 1.8 If needed, the polarity of the sensor bridge gain can be reversed by setting the Gain_polarity bit, which is bit 6 in the SM_config register (see section 3.6.2). Changing the gain polarity is achieved by inverting the chopper clock. Table 2.3 gives the settings for the Gain_polarity bit. This feature enables applying a sensor to the ZSSC3218 with swapped input signals at INN and INP; e.g., to avoid crossing wires for the final sensor module’s assembly. Table 2.3 * Gain Polarity Gain_polarity (SM_config Bit 6) Gain Setting Description 0 +1 No polarity change. 1 -1 Gain polarity is inverted. The register name SM_config is used for general register content and effect explanations for both SM_config1 and SM_config2 as the registers’ bit assignments are exactly the same for both registers. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 13 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 2.3.2. Analog-to-Digital Converter An analog-to-digital converter (ADC) is used to digitize the amplifier signal. To allow optimizing the trade-off between conversion time and resolution, the resolution can be programmed from 12-bit to 18-bit (Adc_bits, SM_config register; section 3.6.2). The ADC processes differential input signals. Table 2.4 ADC Conversion Times for a Single Analog-to-Digital Conversion Resolution (Bits) Conversion Time in s (typical) 12 140 13 185 14 250 15 335 16 470 17 640 18 890 The ADC can perform an offset shift in order to adapt input signals with offsets to the ADC input range. The shift feature is enabled by setting SM_config register’s bit [15] = 1 (Shift_method = 1). The respective analog offset shift can be set up with bits [14:12], Offset in SM_config. The offset shift causes the ADC to perform an additional amplification of the ADC’s input signal by factor 2. This must be considered for a correct analog sensor setup by means of the pre-amplifier’s gain, the ADC offset shift, and the potential ADC gain. The overall analog amplification 𝐺𝑎𝑖𝑛𝑡𝑜𝑡𝑎𝑙 = 𝐺𝑎𝑖𝑛𝑎𝑚𝑝1 ∙ 𝐺𝑎𝑖𝑛𝑎𝑚𝑝2 ∙ 𝐺𝑎𝑖𝑛𝐴𝐷𝐶 can be determined for the following potential use cases: If no offset shift is selected, i.e., Shift_method = 0 and Offset = 000 in SM_config, 𝐺𝑎𝑖𝑛𝑡𝑜𝑡𝑎𝑙 = 𝐺𝑎𝑖𝑛𝑎𝑚𝑝1 ∙ 𝐺𝑎𝑖𝑛𝑎𝑚𝑝2 ∙ 1 If ADC offset shift is selected, i.e., Shift_method = 1 (Offset is arbitrary) in SM_config, 𝐺𝑎𝑖𝑛𝑡𝑜𝑡𝑎𝑙 = 𝐺𝑎𝑖𝑛𝑎𝑚𝑝1 ∙ 𝐺𝑎𝑖𝑛𝑎𝑚𝑝2 ∙ 2 Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 14 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Table 2.5 ADC Offset Shift Offset Shift in ADC SM_config Bit 15 (Shift_method) Offset: SM_config Bit 14 Offset: SM_config Bit 13 Offset: SM_config Bit 12 GainADC Compensation of Percentage Offset in Input Signal 0 0 0 0 1 0% 1 0 0 0 2 0% 1 0 0 1 2 6.75% 1 0 1 0 2 12.50% 1 0 1 1 2 19.25% 1 1 0 0 2 25.00% 1 1 0 1 2 31.75% 1 1 1 0 2 38.50% 1 1 1 1 2 43.25% Note: If no offset shift will be performed and the ADC will not apply the additional gain of factor 2 (leading to GainADC = 1), then Shift_method = 0 and Offset = 000 in SM_config must be selected. Any other setup with Shift_method = 0 and Offset ≠ 000 leads to erroneous analog setups. Table 2.6 Typical Conversion Times vs. Noise Performance with Full Sensor Signal Conditioning for AZSM, SM, AZTM, and TM (Bridge-Type Sensor) 1) Typical Measurement Duration , Typical 3-Sigma Noise for SSC2) MEASURE, (AAHEX) Corrected Output (ms) (counts) ADC Resolution: Temperature Sensor ADC Resolution: External Sensor 16 12 2.2 2.4 16 13 2.3 2.5 16 14 2.4 3.0 16 15 2.6 4.4 16 16 2.8 5.7 16 17 3.2 10.5 16 18 3.7 18.0 1) Measurement duration is defined as the time from the high/low transition at the EOC pin at the beginning of the measurement until the low/high back-transition of the EOC signal at the end of a single measurement in Sleep Mode. 2) Reference noise values normalized to the respective external sensor’s ADC resolution, obtained with the following setup: 20kΩ sensor bridge, 25°C, Gain=52, Offset=25%, VDD=1.8V. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 15 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 2.3.3. Selection of Gain and Offset – Sensor System Dimensioning The optimal gain (and offset) setup for a specific sensor element can be determined by the following steps: 1) Collect sensor element’s characteristic, statistical data (over temperature, ambient sensor parameter, and over production tolerances): a. Minimum differential output voltage: Vmin b. Maximum differential output voltage: Vmax Note: The best possible setup can only be determined if the absolute value of Vmax is bigger than the absolute value of Vmin. If this is not the case, the gain polarity should be reversed by means of the Gain_polarity bit in the MTP’s SM_config register. 2) Calculate: a. Common mode level, i.e. differential offset of the sensor output: 𝑉𝐶𝑀 = 0.5 ∙ (𝑉𝑚𝑎𝑥 + 𝑉𝑚𝑖𝑛 ) b. Relative or percentage offset of the sensor output: 𝑂𝑓𝑓𝑠𝑒𝑡𝑠𝑒𝑛𝑠𝑜𝑟 [%] = 𝑉𝐶𝑀 𝑉𝑚𝑎𝑥 – 𝑉𝑚𝑖𝑛 ∙ 100% 3) Determine which of the two following cases is valid. a. If Offsetsensor[%] > 43% then select Offset = 111 (i.e., 43.25%) b. If 0% < Offsetsensor[%] ≤ 43% then select Offset ≤ Offsetsensor[%] (Offset setup value; see Table 2.5) 4) The totally required, optimum gain can be determined as 𝐺𝑎𝑖𝑛𝑡𝑜𝑡𝑎𝑙,𝑜𝑝𝑡 = 1.4𝑉 𝑂𝑓𝑓𝑠𝑒𝑡𝑠𝑒𝑛𝑠𝑜𝑟 ) 100 𝑉𝑚𝑎𝑥 ∙(1− then select nearest gain to Gaintotal,opt, where Gaintotal ≤ Gaintotal,opt 5) The gain setup can be separated into the three factors Gainamp1, Gainamp2 (for the 2-stage amplifier) and GainADC (1 for no-shift or 2 for shift operation) according to: Gaintotal = Gainamp1 ∙ Gainamp2 ∙ GainADC . a. If no offset shift is performed (Shift_method = 0 and Offset = 000), the amplifier gain is Gaintotal b. If an offset shift is performed (Shift_method = 1), the amplifier gain is 0.5·Gaintotal Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 16 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 2.3 Gain and Offset Setup VDDB INP A Gainamp1 Sensor Bridge Gainamp2 INN DSP SPI GainADC PreAmplifier I²C™ D Offset VSSB Vdifferential, IN VAMP1, OUT VAMP2, OUT VADC, IN Digital ADC Out, 18bit 1.4V 131k 0V Gainamp1 Gainamp2 GainADC , -Offset 0V digitize zo o m -1.4V -131k 2.3.4. Temperature Measurement The ZSSC3218 provides an internal temperature sensor measurement to allow compensation for temperature effects. See section 1.3 for the temperature sensor resolution. The temperature output signal is a differential voltage that is adapted by the amplifier for the ADC input. For temperature measurements, the respective settings are defined and programmed in the MTP by ZMDI. 2.3.5. External Sensor Supply: Bridge Sensors The ZSSC3218 provides dedicated supply pins VDDB and VSSB for resistive bridge-type sensors (bit [11]=0 in SM_config, MTP registers 12HEX or 16HEX). The ADC reference voltages for the sensor bridge measurement are derived from these internal voltages such that bridge supply disturbances are suppressed. The current drive ability of VDDB is limited (see IVDDB in section 1.2). 2.3.6. External Sensor: Absolute Voltage Source Sensors The ZSSC3218 can alternatively process signals from an absolute-voltage source sensor, e.g. a thermopile element. The respective input-type selection can be done with bit[11]=1 in SM_config, MTP registers 12HEX or 16HEX. The respective sensor element must be connected between the pins INP and INN, whereas INN is internally connected to the ZSSC3218’s analog ground (not! being VSSB). VDDB and VSSB should not be connected if an absolute-voltage source sensor is applied. The offset shift should be set to maximum in this case, Shift_method = 1 and Offset = 111 in SM_config. The required gain can be determined according to the procedure described in section 2.3.3. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 17 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 2.4. 2.4.1. Digital Section Digital Signal Processor (DSP) Core The “DSP Core” block performs the algorithm for correcting the sensor signal. The required coefficients are stored in the MTP memory. When the measurement results are available, the “end of conversion” signal is set at the EOC pin if no interruptthreshold has been set up (bits[8:7]=00 in memory register 02HEX). The internal EOC information is valid only if both the measurement and calculation have been completed. Alternatively, the EOC pin can indicate exceeding or underrunning of a certain threshold or leaving of valid-result range as described in section 3.3. 2.4.2. MTP Memory The ZSSC3218’s memory is designed with a real MTP structure. The memory is organized in 16-bit registers that can be re-written multiple (at least 1000) times. The user has access to a 57 x 16-bit storage area for values such as calibration coefficients. The required programming voltage is generated internally in the ZSSC3218. A checksum (generation with command 90HEX) is evaluated be for integrity-check purposes of the entire memory. 2.4.3. Clock Generator The clock generator provides approximately 4MHz, and 1MHz clock signals as the time base for IC-internal signal processing. The frequency is trimmed during production test. 2.4.4. Power Supervision The power supervision block as a part of the voltage regulator combined with the digital section monitors all power supplies to ensure a defined reset of all digital blocks during power-up or power supply interruptions. “Brown-out” cases at the supply that do not meet the power-on reset (POR) requirements (see Table 1.3), must be resolved with a reset pulse at the RES pin. 2.4.5. Interface † 2 The ZSSC3218 can communicate with the user’s communication master or PC via an SPI or I C™ interface . The interface type is selectable with the very first activity at the interface after power-up or reset, with the first activity being 2 TM a. If the first command is an I C command and SS pin has been inactive until receiving this command, 2 TM the ZSSC3218 enters I C mode. b. If the first interface action is the SS pin being set to active (HIGH-active or LOW-active depending on SS_polarity bit[9] in memory interface register 02HEX), then the ZSSC3218 enters SPI mode. During the initiation sequence (after power-up or reset), any potential transition on SS is ignored. Switching to the SPI mode is only possible after the power-up sequence. If SS is not connected, the SS pin internal pull-up keeps 2 TM the ZSSC3218 in I C mode. To also provide interface accessibility in Sleep State (all features inactive except for the digital interface logic), the interface circuitry is directly supplied by VDD. † Functional I2C™ interface properties correspond to the NXP I²C™ bus specification Rev. 0.3 (June 2009). Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 18 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3 Functional Description 3.1. Power Up Specifications for this section are given in sections 1.2 and 1.3. On power-up, the ZSSC3218 communication interface is able to receive the first command after a time t STA1 from when the VDD supply is within operating specifications. The ZSSC3218 can begin the first measurement after a time of tSTA2, from when the VDD supply is operational. Alternatively, instead of a power-on-reset, a reset and new power-up-sequence respectively can be triggered by an IC-reset signal (high low) at RES pin. The wake up time from Sleep State to Active State (see section 3.4) after receiving the activating command is defined as tWUP1 and tWUP2. In Command Mode, subsequent commands can be sent after tWUP1. The first measurement starts after tWUP2 if a measurement request was sent. 3.2. Measurements Available measurement procedures are AZSM: auto-zero (external) sensor measurement SM: (external) sensor measurement AZTM: auto-zero temperature measurement TM: temperature measurement AZSM: The configuration is loaded for measuring the external sensor; i.e., a resistive bridge or an absolute voltage source. The “Multiplexer” block connects the amplifier input to the AGND analog ground reference. An analog-to-digital (A2D) conversion is performed so that the inherent system offset for the respective configuration is converted by the ADC to a digital word with a resolution according to the respective MTP configuration. SM: The configuration is loaded for measuring the external sensor; i.e. a resistive bridge or an absolute voltage source. The “Multiplexer” block connects the amplifier input to the INP and INN pins. An A2D conversion is performed. The result is a digital word with a resolution according to the MTP configuration. AZTM: The configuration for temperature measurements is loaded. The “Multiplexer” block connects the amplifier input to AGND. An analog-to-digital conversion is performed so that the inherent system offset for the temperature configuration is converted by the ADC with a resolution according to the respective MTP configuration. TM: The configuration for temperature measurements is loaded. The “Multiplexer” block connects the amplifier input to the internal temperature sensor. An A2D conversion is performed. The result is a digital word with a resolution according to the MTP configuration. The typical application’s measurement cycle is a complete SSC measurement (using the commands AAHEX to AFHEX; see section 3.4.1) with AZSM, SM, AZTM, and TM followed by a signal correction calculation. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 19 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.3. Interrupt (EOC Pin) The EOC pin can be programmed to operate either as a pure “measurement busy” and end-of-conversion indicator or as a configurable interrupt indicator. The respective basic operation must be programmed to the INT_setup bits [8:7] in register 02HEX (see Table 3.5). In addition, one or two 24-bit-quantized thresholds can be programmed (TRSH1 and TRSH2 in memory registers 13HEX, 14HEX, and 15HEX). The respective thresholds are programmed left-aligned in the memory; i.e., they must be programmed with the threshold’s MSB in the memory register’s MSB, etc. The number of LSB threshold bits that are used is equal to the number of bits for the selected ADC resolution (determined by the Adc_bits field in registers 12HEX and 16HEX); unused LSB bits are ignored. The interrupt functionality is only available for digital values from the SSC-calculation unit (i.e., after sensor signal conditioning); raw values cannot be monitored by the interrupt feature. Figure 3.1 shows the different setup options and the respective response at the EOC pin. The use of the interrupt functionality is recommended for cyclic operation (command ABHEX with the respective power-down setup in the Interface Configuration memory register 02HEX). The EOC level continuously represents the respective SSC-measurement results only during cyclic operation. For single or oversample measurement requests without cyclic operation, the EOC output signal is reset to logical zero at the beginning of each new measurement, even though the interrupt thresholds are considered correctly at the end of each measurement (setting EOC to logical one or zero is dependent on the interrupt setup). Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 20 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.1 Interrupt Functionality Measurement Result INT_setup=01: Measurement < threshold1 Measurement Result max. INT_setup=10: Measurement > threshold1 max. threshold 1 threshold 1 0 0 Time Time EOC / INT EOC / INT 1 1 0 0 Time Time INT_setup=11 Measurement Result Case A: threshold1 > threshold2 Measurement Result max. max. threshold 1 threshold 2 threshold 2 threshold 1 0 0 Time EOC / INT 1 0 0 Time November 17, 2014. Time EOC / INT 1 Data Sheet Case B: threshold1 < threshold2 Time © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 21 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.4. Operational Modes Figure 3.2 illustrates the ZSSC3218 power-up sequence and subsequent operation depending on the selected 2 interface communication mode (I C™ or SPI) as determined by interface-related first activities after power-up or reset. If the first command after power-up is a valid I²C™ command, the interface will function as an I²C™ interface until the next power-on-reset. If there is no valid I²C™ command, but an active signal at the SS pin is detected as the first valid activity, then the interface will respond as an SPI slave. With either interface, after the voltage regulators are switched on, the ZSSC3218’s low-voltage section (LV) is active while the related interface configuration information is read from memory. Then the LV section is switched off, the ZSSC3218 goes into Sleep State, and the interface is ready to receive commands. The interface is always powered by VDD, so it is referred to as the high voltage section (HV). See Table 3.1 for definitions of the commands. Figure 3.3 shows the ZSSC3218 operation in Normal Mode (with two operation principles: “Sleep” and “Cyclic”) and Command Mode, including when the LV and HV sections are active as indicated by the color legend. The Normal Mode automatically returns to Sleep State after executing the requested measurements, or periodically wakes up and conducts another measurement according to the setting for the sleep duration configured by CYC_period (bits[14:12] in memory register 02 HEX). In Command Mode, the ZSSC3218 remains active if a dedicated command (Start_NOM) is sent, which is helpful during calibration. Command Mode can only be entered if Start_CM is the first command received after POR. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 22 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.2 Operational Flow Chart: Power Up I2CTM slave address is loaded, and SS_polarity determines if SS pin is active high or low IC Power On Color Legend: LV Operation Command:= load I/O setup HV Operation IO_mode = I2C™ no I2C™ Address / CMD Valid? no SS Pin Active? yes IO_mode:=SPI Power up LV Power up LV Data/Status from LV Save: IC ID / Data / Status LV Operation Data/Status from LV LV Operation Save: Setup / Data / Status SPI Interface I2C™ Interface From this point until next POR, the interface selection is fixed yes CommandMode ==active || Test==1 yes CommandMode ==active || Test==1 no no Power Down (switch off LV and wait for command) no yes no no Power Down (switch off LV and wait for command) Receive: Command no Received CMD ID == IC-ID RST(SS)==1 yes yes Receive: Command Read_bit == 1 (Data Fetch) yes Execute: Data Fetch NOP yes Execute: Data Fetch Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 23 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.3 Operational Flow Chart: Command Mode and Normal Mode (Sleep and Cyclic) Start LV Color Legend: LV Operation Get Command from HV HV Operation CYCLIC_ACTIVE? yes no CMD==Start_CM yes no SETUP_LV:= New Command’s Setup New command CM active Case (Command) New Measurement Command or STOP_CYCLE? INVALID_CMD REGULAR_CMD Power up all LV Receive: Command INVALID_CMD STOP_CYCLE no Data/Status from LV Keep Existing SETUP_LV Do: SETUP_LV Case (Command) Power Down all LV Except Oscillator Execute: Command CM inactive REGULAR_CMD Cyclic Measurement? no yes CYCLIC_ACITVE! to HV Data/Status from LV Safe Command and SETUP_LV Reset LV Start_NOM Count Waiting Period Execute: Command End LV Command Mode Sleep Mode Data Sheet November 17, 2014. Cyclic Mode © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 24 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.4.1. 2 SPI/I C™ Commands 2 The SPI/I C™ commands supported by the ZSSC3218 are listed in Table 3.1. The command to read an address in the user memory is the same as its address. The command to write to an address in user memory is the address plus 40HEX. There is a ZMDI-reserved section of memory that can be read but not over-written by the user. Table 3.1 2 SPI/I C™ Commands Note: Every return starts with a status byte followed by the data word as described in section 3.5.1. Command (Byte) Return Description Normal Mode Command Mode 00HEX to 39HEX 16-bit user data Read data in the user memory address (00HEX to 39HEX) matching the command (might not be using all addresses). Yes Yes 3AHEX to 3FHEX 16-bit ZMDI-reserved memory data Read data in ZMDI-reserved memory at address (3AHEX to 3FHEX). Yes Yes 40HEX to 79HEX followed by data (0000HEX to FFFFHEX) — Write data to user memory at address specified by command minus 40HEX (addresses 00HEX to 39HEX respectively; might not be using all addresses). Yes Yes 90HEX — Calculate and write memory checksum (CRC). Yes Yes A0HEX to A7HEX followed by XXXXHEX 24-bit formatted raw data Get_Raw This command can be used to perform a measurement and write the raw ADC data into the output register. The LSB of the command determines how the AFE configuration register is loaded for the Get_Raw measurement (see Table 3.2). Yes Yes A8HEX — Start_NOM Exit Command Mode and transition to Normal Mode (Sleep or Cyclic). No Yes A9HEX — Start_CM Exit Normal Mode and transition to Command Mode (as very first command after power-up). Yes No Measure Trigger full measurement cycle (AZSM, SM, AZTM, and TM, as described in section 3.2) and calculation and storage of data in the output buffer using the configuration from MTP. Yes Yes (see Table 3.2) AAHEX Data Sheet November 17, 2014. 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 25 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Command (Byte) Return Description Normal Mode Command Mode ABHEX 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data Measure Cyclic This command triggers a continuous full measurement cycle (AZSM, SM, AZTM, and TM; see section 3.2) and calculation and storage of data in the output buffer using the configuration from MTP followed by a pause determined by CYC_period (bits[14:12] in memory register 02HEX). Yes Yes ACHEX 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data Oversample-2 Measure Mean value generation: 2 full measurements are conducted (as in command AAHEX), the measurements’ mean value is calculated, and data is stored in the output buffer using the configuration from MTP; no power down or pause between the 2 measurements. Yes Yes ADHEX 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data Oversample-4 Measure Mean value generation: 4 full measurements (as in command AAHEX) are conducted, the measurements’ mean value is calculated, and data is stored in the output buffer using the configuration from MTP; no power down or pause between the 4 measurements. Yes Yes AEHEX 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data Oversample-8 Measure Mean value generation: 8 full measurements (as in command AAHEX) are conducted, the measurements’ mean value is calculated, and data is stored in the output buffer using the configuration from MTP; no power down or pause between the 8 measurements. Yes Yes AFHEX 24-bit formatted fully corrected sensor measurement data + 24-bit corrected temperature data Oversample-16 Measure Mean value generation: 16 full measurements (as in command AAHEX) are conducted, the measurements’ mean value is calculated, and data is stored in the output buffer using the configuration from MTP; no power down or pause between the 16 measurements. Yes Yes Select SM_config1 register (12HEX in memory) For any measurement using the memory contents for the analog front-end and sensor setup, the respective setup is loaded from the SM_config1 register; status bit[1]==0 (default). Yes Yes B0HEX Data Sheet November 17, 2014. — © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 26 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Command (Byte) Return Description Normal Mode Command Mode B1HEX — Select SM_config2 register (16HEX in memory) For any measurement using the memory contents for the analog front-end and sensor setup, the respective setup is loaded from the SM_config2 register, status bit[1]==1 Yes Yes BFHEX — STOP_CYC This command causes a powerdown halting the update / cyclic measurement operation and causing a transition to Normal-Sleep operation. Yes Yes FXHEX Status followed by last 24-bit data NOP Only valid for SPI (see sections 3.5.1 and 3.5.2). Yes Yes Table 3.2 Get_Raw Commands Command Measurement AFE Configuration Register A0HEX followed by 0000HEX SM – Sensor Measurement SM_config1 register or SM_config2 register. A1HEX followed by ssssHEX SM – Sensor Measurement ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the definitions for SM_config (see Table 3.5). A2HEX followed by 0000HEX SM-AZSM – Auto-Zero Corrected 1) Sensor Measurement SM_config A3HEX followed by ssssHEX SM-AZSM – Auto-Zero Corrected 2) Sensor Measurement ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the definitions for SM_config. A4HEX followed by 0000HEX TM – Temperature Measurement ZMDI-defined register A5HEX followed by ssssHEX TM – Temperature Measurement ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the definitions for SM_config and valid for temperature measurement in this case (bits [15:12] will be ignored). A6HEX followed by 0000HEX TM-AZTM – Auto-Zero Corrected 1) Temperature Measurement ZMDI-defined register A7HEX followed by ssssHEX TM-AZTM – Auto-Zero Corrected 2) Temperature Measurement ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of these configuration bits must be according to the definitions for SM_config and valid for temperature measurement in this case (bits [15:12] will be ignored). 1) Recommended for raw data collection during calibration coefficient determination using the measurement setups pre-programmed in MTP. 2) Recommended for raw data collection during calibration coefficient determination using un-programmed (not in MTP), external measurement setups; e.g., for evaluation purposes. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 27 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.5. Communication Interface 3.5.1. Common Functionality Commands are handled by the command interpreter in the LV section. Commands that need additional data are not treated differently than other commands because the HV interface is able to buffer the command and all the data that belongs to the command and the command interpreter is activated as soon as a command byte is received. Every response starts with a status byte followed by the data word. The data word depends on the previous 2 command. It is possible to read the same data more than once if the read request is repeated (I C™) or a NOP command is sent (SPI). If the next command is not a read request (I²C™) or a NOP (SPI), it invalidates any previous data. The ZSSC3218 supports the parallel setup of two amplifier-ADC-configurations using SM_config1 and SM_config2. Switching between the two setups can be done with the commands B0HEX and B1HEX. Note that the respective activation command must always be sent prior to the measurement request. The status byte contains the following bits in the sequence shown in Table 3.3: Power indication (bit 6): 1 if the device is powered (VDDB on); 0 if not powered. This is needed for the SPI Mode where the master reads all zeroes if the device is not powered or in power-on reset (POR). Busy indication (bit 5): 1 if the device is busy, which indicates that the data for the last command is not available yet. No new commands are processed if the device is busy. Note: The device is always busy if cyclic measurement operation has been set up and started. Currently active ZSSC3218 mode (bits [4:3]): 00 = Normal Mode; 01 = Command Mode; 1X = ZMDI reserved. Memory integrity/error flag (bit 2): 0 if integrity test passed; 1 if test failed. This bit indicates whether the checksum-based integrity check passed or failed. The memory error status bit is calculated only during the power-up sequence, so a newly written CRC will only be used for memory verification and status update after a subsequent ZSSC3218 power-on reset (POR) or reset by means of the RES pin. Config Setup (bit 1): This bit indicates which SM_config register is being used for the active configuration: SM_config1 (12HEX) or SM_config2 (16HEX). The two alternate configuration setups allow for two different configurations of the external senor channel in order to support up to two application scenarios with the use of only one sensor-ZSSC3218 pair. This bit is 0 if SM_config1 was selected (default). This bit is 1 if SM_config2 was selected. ALU saturation (bit 0): If the last command was a measurement request, this bit is 0 if any intermediate value and the final SSC result are in a valid range and no SSC-calculation internal saturation occurred in the arithmetic logic unit (ALU). If the last command was a measurement request, this bit is 1 if an SSCcalculation internal saturation occurred. This bit is also 0 for any non-measurement command. Table 3.3 General Status Byte Bit 7 6 5 Meaning 0 Powered? Busy? Data Sheet November 17, 2014. 4 3 Mode 2 1 0 Memory error? Config Setup ALU Saturation © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 28 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Table 3.4 Mode Status Status[4:3] Mode 00 Normal Mode (sleep and cyclic operations) 01 Command Mode 10 ZMDI reserved 11 ZMDI reserved Further status information can be provided by the EOC pin. The EOC pin is set high when a measurement and calculation have been completed (if no interrupt threshold is used, i.e. INT_setup==00 BIN; see section 3.3). 3.5.2. SPI The SPI Mode is available if the very first interface activity after ZSSC3218 power-up is an active signal at the SS pin. The polarity and phase of the SPI clock are programmable via the CKP_CKE setting in bits [11:10] in address 02HEX as described in Table 3.5. CKP_CKE is two bits: CPHA (bit 10), which selects which edge of SCLK latches data, and CPOL (bit 11), which indicates whether SCLK is high or low when it is idle. The polarity of the SS signal and pin are programmable via the SS_polarity setting (bit 9). The different combinations of polarity and phase are illustrated in the figures below. Figure 3.4 SPI Configuration CPHA=0 CPHA=0 SCLK (CPOL=0) SCLK (CPOL=1) MOSI MSB Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 LSB MISO MSB Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 LSB /SS SAMPLE Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 29 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.5 SPI Configuration CPHA=1 CPHA=1 SCLK (CPOL=0) SCLK (CPOL=1) MOSI MSB Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 LSB MISO MSB Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 LSB /SS SAMPLE In SPI mode, each command except NOP is started as shown in Figure 3.6. After the execution of a command (busy = 0), the expected data can be read as illustrated in Figure 3.7 or if no data are returned by the command, the next command can be sent. The status can be read at any time with the NOP command (see Figure 3.8). Figure 3.6 SPI Command Request Command Request MOSI Command other than NOP CmdDat <15:8> CmdDat <7:0> MISO Status Data Data Note: A command request always consists of 3 bytes. If the command is shorter, then it must be completed with 0s. The data on MISO depend on the preceding command. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 30 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.7 SPI Read Status Read Status MOSI Command = NOP MISO Status Figure 3.8 SPI Read Data 3.5.3. 2 I C™ 2 2 I C™ Mode will be selected if the very first interface activity after ZSSC3218 power-up is an I C™ command. In 2 I C™ Mode, each command is started as shown in Figure 3.8. Only the number of bytes that are needed for the command must be sent. An exception is the HS-mode where 3 bytes must always be sent as in SPI Mode. After the execution of a command (busy = 0), the expected data can be read as illustrated in Figure 3.11 or if no data are returned by the command, the next command can be sent. The status can be read at any time as described in Figure 3.10. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 31 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 3.9 I2C™ Command Request Command Request (I2C™ Write) S SlaveAddr 0 A Command from master to slave S START condition from slave to master P STOP condition A acknowledge N not acknowledge A P write S SlaveAddr 0 A Command A CmdDat <15:8> A CmdDat <7:0> A P write 2 Figure 3.10 I C™ Read Status Read Status (I2C™ Read) S SlaveAddr 1 A Status N P read 2 Figure 3.11 I C™ Read Data Read Data (I2C™ Read) (a) Example: after the completion of a Memory Read command S SlaveAddr 1 A Status A MemDat <15:8> A MemDat <7:0> N P read (b) Example: after the completion of a Full Measurement command (AAHEX) S SlaveAddr 1 A Status A SensorDat SensorDat SensorDat A A A <15:8> <7:0> <23:16> TempDat <23:16> A TempDat <15:8> A TempDat <7:0> N P read Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 32 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC All mandatory I²C™-bus protocol features are implemented. Optional features such as clock stretching, 10-bit slave address, etc., are not supported by the ZSSC3218’s interface. In I²C-High-Speed Mode, a command consists of a fixed length of three bytes. 3.6. Multiple Time Programmable (MTP) Memory In the ZSSC3218, the memory is organized in 16-bit wide registers and can be programmed multiple times (ca. 1000). There are 57 x 16-bit registers available for customer use. Each register can be re-programmed. Basically, there are two MTP content sectors: Customer Use: ZMDI Use: 3.6.1. accessible by means of regular write operations: 40HEX to 79HEX. It contains the customer ID, interface setup data, measurement setup information, calibration coefficients, etc. only accessible for write operations by ZMDI. The ZMDI sector contains specific trim information and is programmed during manufacturing test by ZMDI. Programming Memory Programming memory is possible with any specified supply voltage level at VDD. The MTP programming voltage itself is generated by means of an integrated charge pump, generating an internal memory programming voltage; no additional, external voltage, other than VDD (as specified) is needed. A single 16-bit register write will be completed within 16ms after the respective programming command has been sent. After the memory is programmed, it must be read again to verify the validity of the memory contents. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 33 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.6.2. Memory Contents Table 3.5 MTP Memory Content Assignments MTP Address Word / Bit Range Default Setting Description Notes / Explanations 00HEX 15:0 0000HEX Cust_ID0 Customer ID byte 0 (combines with memory word 01HEX to form customer ID). 01HEX 15:0 0000HEX Cust_ID1 Customer ID byte 1 (combines with memory word 00HEX to form customer ID). Slave_Addr I²C™ slave address; valid range: 00HEX to 7FHEX (default: 00HEX). Note: address codes 04HEX to 07HEX 2 are reserved for entering the I C™ High Speed Mode. Interface Configuration 6:0 000 0000BIN Interrupt configuration, EOC pin functionality: 00 01 10 8:7 00BIN INT_setup 02HEX 11 End-of-conversion signal 0-1 transition if threshold1 (TRSH1) is exceeded and 1-0 transition if threshold1 is underrun again 0-1 transition if threshold1 is underrun and 1-0 transition if threshold1 is exceeded again EOC is determined by threshold settings (see section 3.3): If (TRSH1 > TRSH2) then EOC/INT (interrupt level) = 0 if (TRSH1 > MEAS ≥ TRSH2) where MEAS is the conditioned measurement result. Otherwise EOC/INT=1. If (TRSH1 ≤ TRSH2) then EOC = 1 if (TRSH1 ≤ MEAS < TRSH2). Otherwise EOC = 0. Determines the polarity of the Slave Select pin (SS) for SPI operation: 9 Data Sheet November 17, 2014. 0BIN SS_polarity 0 Slave Select is active low (SPI and ZSSC3218 are active if SS==0) 1 Slave Select is active high (SPI and ZSSC3218 are active if SS==1) © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 34 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations Clock polarity and clock-edge select—determines polarity and phase of SPI interface clock with the following modes: 11:10 00BIN CKP_CKE 00 SCLK is low in idle state, data latch with rising edge and data output with falling edge 01 SCLK is low in idle state, data latch with falling edge and data output with rising edge 10 SCLK is high in idle state, data latch with falling edge and data output with rising edge 11 SCLK is high in idle state, data latch with rising edge and data output with falling edge Update period (ZSSC3218 sleep time, except oscillator) in cyclic operation: 14:12 15 Data Sheet November 17, 2014. 000BIN 0BIN CYC_period SOT_curve 000 not assigned 001 125ms 010 250ms 011 500ms 100 1000ms 101 2000ms 110 4000ms 111 not assigned Type/shape of second-order curve correction for the sensor signal. 0 parabolic curve 1 s-shaped curve © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 35 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations Signal Conditioning Parameters 03HEX 04HEX 05HEX 06HEX 15:0 15:0 15:0 15:0 0000HEX 0000HEX 0000HEX 0000HEX Offset_S[15:0] Bits [15:0] of the 24-bit-wide sensor offset correction coefficient Offset_S. (The MSBs of this coefficient including sign are Offset_S[23:16], which is bits [15:8] in 0DHEX.) Gain_S[15:0] Bits [15:0] of the 24-bit-wide value of the sensor gain coefficient Gain_S. (The MSBs of this coefficient including sign are Gain_S[23:16], which is bits [7:0] in 0DHEX.) Tcg[15:0] Bits [15:0] of the 24-bit-wide coefficient Tcg for the temperature correction of the sensor gain. (The MSBs of this coefficient including sign are Tcg[23:16], which is bits [15:8] in 0EHEX.) Tco[15:0] Bits [15:0] of the 24-bit-wide coefficient Tco for temperature correction of the sensor offset. (The MSBs of this coefficient including sign are Tco[23:16], which is bits [7:0] in 0EHEX.) SOT_tco[15:0] Bits [15:0] of the 24-bit-wide 2 order term SOT_tco applied to Tco. (The MSBs of this term including sign are SOT_tco[23:16], which is bits[15:8] in 0FHEX.) SOT_tcg[15:0] Bits [15:0] of the 24-bit-wide 2 order term SOT_tcg applied to Tcg. (The MSBs of this term including sign are SOT_tcg[23:16], which is bits[7:0] in 0FHEX.) SOT_sens[15:0] Bits [15:0] of the 24-bit-wide 2 order term SOT_sens applied to the sensor readout. (The MSBs of this term including sign are SOT_sens[23:16], which is bits[15:8] in 10HEX.) Offset_T[15:0] Bits [15:0] of the 24-bit-wide temperature offset correction coefficient Offset_T. (The MSBs of this coefficient including sign are Offset_T[23:16], which is bits[7:0] in 10HEX.) Gain_T[15:0] Bits [15:0] of the 24-bit-wide absolute value of the temperature gain coefficient Gain_T. (The MSBs of this coefficient including sign are Gain_T[23:16], which is bits[15:8] in 11HEX.) SOT_T[15:0] Bits [15:0] of the 24-bit-wide 2 -order term SOT_T applied to the temperature reading. (The MSBs of this coefficient including sign are SOT_T[23:16], which is bit[7:0] in 11HEX.) nd 07HEX 15:0 0000HEX nd 08HEX 15:0 0000HEX nd 09HEX 0AHEX 0BHEX 15:0 15:0 15:0 0000HEX 0000HEX 0000HEX nd 0CHEX 15:0 Data Sheet November 17, 2014. 0000HEX © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 36 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations 7:0 00HEX Gain_S[23:16] Bits [23:16] including sign for the 24-bit-wide sensor gain correction coefficient Gain_S. (The LSBs of this coefficient are Gain_S[15:0] in register 04HEX.) 15:8 00HEX Offset_S[23:16] Bits [23:16] including sign for the 24-bit-wide sensor offset correction coefficient Offset_S. (The LSBs are Offset_S[15:0] in register 03HEX.) Tco[23:16] Bits [23:16] including sign for the 24-bit-wide coefficient Tco for temperature correction for the sensor offset. (The LSBs are Tco[15:0] in register 06HEX.) Tcg[23:16] Bits [23:16] including sign for the 24-bit-wide coefficient Tcg for the temperature correction of the sensor gain. (The LSBs are Tcg[15:0] in register 05HEX.) SOT_tcg[23:16] Bits [23:16] including sign for the 24-bit-wide 2 order term SOT_tcg applied to Tcg. (The LSBs are SOT_tcg[15:0] in register 08HEX.) 0DHEX 00HEX 7:0 0EHEX 15:8 00HEX nd 00HEX 7:0 0FHEX nd 15:8 00HEX SOT_tco[23:16] Bits [23:16] including sign for the 24-bit-wide 2 order term SOT_tco applied to Tco. (The LSBs are SOT_tco[15:0] in register 07HEX.) 7:0 00HEX Offset_T[23:16] Bits [23:16] including sign for the 24-bit-wide temperature offset correction coefficient Offset_T. (The LSBs are Offset_T[15:0] in register 0AHEX.) SOT_sens[23:16] Bits [23:16] including sign for the 24-bit-wide 2 order term SOT_sens applied to the sensor readout. (The LSBs are SOT_sens[15:0] in register 09HEX.) SOT_T[23:16] Bits [23:16] including sign for the 24-bit-wide nd 2 -order term SOT_T applied to the temperature reading. (The LSBs are SOT_T[15:0] in register 0CHEX.) Gain_T[23:16] Bits [23:16] including sign for the 24-bit-wide absolute value of the temperature gain coefficient Gain_T. (The LSBs are Gain_T[15:0] in register 0BHEX.) 10HEX nd 15:8 00HEX 00HEX 7:0 11HEX 15:8 Data Sheet November 17, 2014. 00HEX © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 37 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations Measurement Configuration Register 1 (SM_config1) st Gain setting for the 1 PREAMP stage with Gain_stage1 Gainamp1: 2:0 000BIN Gain_stage1 000 6 001 12 010 20 011 30 100 40 101 60 110 80 111 120 (Might affect noise and accuracy specifications depending on sensor setup) nd Gain setting for the 2 PREAMP stage with Gain_stage2 Gainamp2: 5:3 000BIN Gain_stage2 12HEX 6 0BIN Gain_polarity 000 1.1 001 1.2 010 1.3 011 1.4 100 1.5 101 1.6 110 1.7 111 1.8 Set up the polarity of the sensor bridge’s gain (inverting of the chopper) with 0 positive (no polarity change) 1 negative (180° polarity change) Absolute number of bits for the ADC conversion ADC_bits: 10:7 Data Sheet November 17, 2014. 0000BIN Adc_bits 0000 12-bit 0001 13-bit 0010 14-bit 0011 15-bit 0100 16-bit 0101 17-bit 0110 18-bit 0111 to 1111 not assigned © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 38 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range 11 Default Setting 0BIN Description AbsV_enable Notes / Explanations Enable bit for thermopile input selection (INN connected to AGND, INP connected to absolute voltage source) with AbsV_enable: 0 absolute voltage input disabled (default) 1 absolute voltage input enabled (e.g. for a thermopile) Differential signal’s offset shift in the ADC; compensation of signal offset by x% of input signal: 14:12 000BIN Offset 000 no offset compensation 001 6.75% offset 010 12.5% offset 011 19.25% offset 100 25% offset 101 31.75% offset 110 38.5% offset 111 43.25% offset Note: Bit 15 below must be set to 1 to enable the offset shift. Offset shift method switch: 15 0BIN Shift_method 0 No offset shift. Offset (bits [14:12] in 12HEX) must be set to 000BIN; GainADC = 1 1 Offset shift ADC; GainADC = 2 13HEX 15:0 0000HEX TRSH1[15:0] Bits [15:0] of the 24-bit-wide interrupt threshold1, TRSH1. (The MSB bits for this threshold are TRSH1[23:16], which is bits [7:0] of register 15HEX.) 14HEX 15:0 0000HEX TRSH2[15:0] Bits [15:0] of the 24-bit-wide interrupt threshold2, TRSH2. (The MSB bits for this threshold are TRSH2[23:16], which is bits[15:8] of register 15HEX.) 7:0 00HEX TRSH1[23:16] Bits [23:16] of the 24-bit-wide interrupt threshold1, TRSH1. (The LSB bits for this threshold are TRSH1[15:0], which is bits[15:0] of register 13HEX.) 15:8 00HEX TRSH2[23:16] Bits [23:16] of the 24-bit-wide interrupt threshold2, TRSH2. (The LSB bits for this threshold are TRSH2[15:0], which is bits[15:0] of register 14HEX.) 15HEX Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 39 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations Measurement Configuration Register 2 (SM_config2) st Gain setting for the 1 PREAMP stage with Gain_stage1 Gainamp1: 2:0 000BIN Gain_stage1 000 6 001 12 010 20 011 30 100 40 101 60 110 80 111 120 (Might affect noise and accuracy specifications depending on sensor setup) nd Gain setting for the 2 PREAMP stage with Gain_stage2 Gainamp2: 5:3 000BIN Gain_stage2 16HEX 6 0BIN Gain_polarity 000 1.1 001 1.2 010 1.3 011 1.4 100 1.5 101 1.6 110 1.7 111 1.8 Set up the polarity of the sensor bridge’s gain (inverting of the chopper) with 0 positive (no polarity change) 1 negative (180° polarity change) Absolute number of bits for the ADC conversion ADC_bits: 10:7 Data Sheet November 17, 2014. 0000BIN Adc_bits 0000 12-bit 0001 13-bit 0010 14-bit 0011 15-bit 0100 16-bit 0101 17-bit 0110 18-bit 0111 to 1111 not assigned © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 40 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range 11 Default Setting 0BIN Description AbsV_enable Notes / Explanations Enable bit for thermopile input selection (INN connected to AGND, INP connected to absolute voltage source) with AbsV_enable: 0 absolute voltage input disabled (default) 1 absolute voltage input enabled (e.g. for a thermopile) Differential signal’s offset shift in the ADC; compensation of signal offset by x% of input signal: 14:12 000BIN Offset 000 no offset compensation 001 6.75% offset 010 12.5% offset 011 19.25% offset 100 25% offset 101 31.75% offset 110 38.5% offset 111 43.25% offset Note: Bit 15 below must be set to 1 to enable the offset shift. Offset shift method switch: 15 0BIN Shift_method 0 No offset shift. Offset (bits[14:12] in 16HEX) must be set to 000BIN; GainADC = 1 1 Offset Shift ADC, GainADC = 2 Post-Calibration Offset Correction Coefficients 17HEX 15:0 0000HEX SENS_Shift[15:0] Bits [15:0] of the post-calibration sensor offset shift coefficient SENS_Shift. (The MSB bits of SENS_Shift are bits [7:0] of register 19HEX.) 18HEX 15:0 0000HEX T_Shift[15:0] Bits [15:0] of the post-calibration temperature offset shift coefficient T_Shift. (The MSB bits of T_Shift are bits [15:8] of register 19HEX.) 7:0 00HEX SENS_Shift[23:16] Bits [23:16] of the post-calibration sensor offset shift coefficient SENS_Shift. (The LSB bits of SENS_Shift are in register 17HEX.) 15:8 00HEX T_Shift[23:16] Bits [23:16] of the post-calibration temperature offset shift coefficient T_Shift. (The LSB bits of T_Shift are in register 18HEX.) 19HEX Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 41 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC MTP Address Word / Bit Range Default Setting Description Notes / Explanations Free Memory – Arbitrary Use 20HEX 15:0 0000HEX Not assigned (e.g., can be used for Cust_IDx customer identification number) 21HEX 15:0 0000HEX Not assigned (e.g., can be used for Cust_IDx customer identification number) Not assigned (e.g., can be used for Cust_IDx customer identification number) … 37HEX 15:0 0000HEX Not assigned (e.g., can be used for Cust_IDx customer identification number) 38HEX 15:0 0000HEX Not assigned (e.g., can be used for Cust_IDx customer identification number) - Generated (checksum) for the entire memory through a linear feedback shift register (LFSR); signature is checked on power-up to ensure memory content integrity 39HEX 15:0 Checksum The memory integrity checksum (referred to as CRC) is generated through a linear feedback shift register with the following polynomial: 16 15 2 g(x) = x + x + x + 1 with the initialization value: FFFFHEX. If the CRC is valid, then the “Memory Error” status bit is set to 0. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 42 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.7. Calibration Sequence Calibration essentially involves collecting raw signal and temperature data from the sensor-ZSSC3218 system for different known sensor-element values (i.e., for a resistive bridge or an absolute voltage source) and temperatures. This raw data can then be processed by the calibration master (assumed to be the user’s computer), and the calculated calibration coefficients can then be written to on-chip memory. Here is a brief overview of the three mains steps involved in calibrating the ZSSC3218. 1. Assigning a unique identification to the ZSSC3218. This identification is written to shadow RAM and programmed in MTP memory. This unique identification can be stored in the two 16-bit registers dedicated to the customer ID. It can be used as an index into a database stored on the calibration PC. This database will contain all the raw values of the connected sensor-element readings and temperature readings for that part, as well as the known sensor-element measurand conditions and temperature to which the sensor-element was exposed. 2. Data collection. Data collection involves getting uncorrected (raw) data from the external sensor at different known measurand values and temperatures. Then this data is stored on the calibration master using the unique identification of the device as the index to the database. 3. Coefficient calculation and storage in MTP memory. After enough data points have been collected to calculate all the desired coefficients, the coefficients can be calculated by the calibration master. Then the coefficients can be programmed to the MTP memory. Result. The sensor signal and the characteristic temperature effect on output will be linearized according to the setup-dependent maximum output range. It is essential to perform the calibration with a fixed programming setup during the data collection phase. In order to prevent any accidental misprocessing, it is further recommended to keep the MTP memory setup stable during the entire calibration process as well as in the subsequent operation. A ZSSC3218 calibration only fits the setup used during its calibration. Changes of functional parameters after a successful calibration can decrease the precision and accuracy performance of the ZSSC3218 as well as of the entire application. The ZSSC3218 supports operation with different sensor setups by means of the SM_config1 and SM_config2 registers. However, only one calibration coefficient set is supported. Therefore, either an alternative ZSSC3218external signal calibration using the alternate SM_config settings must be performed to ensure that the programmed SSC coefficients are valid for both setups, or a full reprogramming of the SSC coefficients must be performed each time the sensor setup is changed. The selection of the external sensor setup (i.e., the AFE configuration) can be done with the interface commands B0HEX and B1HEX. 3.7.1. Calibration Step 1 – Assigning Unique Identification Assign a unique identification number to the ZSSC3218 by using the memory write command (40HEX + data and 41HEX + data; see Table 3.1 and Table 3.5) to write the identification number to Cust_ID0 at memory address 00HEX and Cust_ID1 at address 01HEX as described in section 3.6.1. These two 16-bit registers allow for more than 4 billion unique devices. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 43 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Calibration Step 2 – Data Collection 3.7.2. The number of unique points (measurand and/or temperature) at which calibration must be performed generally depends on the requirements of the application and the behavior of the sensor in use. The minimum number of points required is equal to the number of correction coefficients to be corrected with a minimum of three different temperatures at three different sensor values. For a full calibration resulting in values for all 7 possible (external) sensor coefficients and 3 possible temperature coefficients, a minimum of 7 pairs of sensor with temperature measurements must be collected. Within this minimum field of 3 measurand measurements x 3 temperature measurements, data must be collected for the specific value pairs (at known conditions) and then processed to calculate the coefficients. In order to obtain the potentially best and most robust coefficients, it is recommended that measurement pairs (temperature vs. measurand) be collected at the outer corners of the intended operation range or at least at points that are located far from each other. It is also essential to provide highly precise reference values as nominal, expected values. The measurement precision of the external calibration-measurement equipment should be ten times more accurate than the expected ZSSC3218 output accuracy after calibration in order to avoid accuracy losses caused by the nominal reference values (e.g., measurand signal and temperature deviations). Note: The coefficients SENS_shift and T_shift must not be determined during this calibration step. These coefficients can be pre-determined as zero until after initial calibration. Note: An appropriate selection of measurement pairs can significantly improve the overall system performance. The determination of the measurand-related coefficients will use all of the measurement pairs. For the temperature-related correction coefficients, 3 (at three different temperatures) of the measurement pairs will be used. Note: There is an inherent redundancy in the 7 sensor-related and 3 temperature-related coefficients. Since the temperature is a necessary output (which also needs correction), the temperature-related information is mathematically separated, which supports faster and more efficient DSP calculations during the normal usage of the sensor-ZSSC3218 system. The recommended approach for data collection is to make use of the rawmeasurement commands described in Table 3.2. For external sensor values, either of the following commands can be used depending on the user’s requirements: A2HEX + 0000HEX A3HEX + ssssHEX single sensor measurement for which the configuration register will be loaded from the SM_Config1 register (12HEX in MTP); preprogramming the measurement setup in the MTP is required. single sensor measurement for which the SM_config configuration register (Gain, ADC, Offset, etc.) will be loaded as the user’s configuration ssssHEX, which must be provided externally via the interface as the data part of this command. For temperature values, either of the following commands can be used depending on the user’s requirements: A6HEX + 0000HEX Data Sheet November 17, 2014. single temperature measurement for which the configuration register will be loaded from an internal temperature configuration register (preprogrammed by ZMDI in the MTP); preprogramming of the respective configuration is done by ZMDI prior to ZSSC3218 delivery. This is the recommended approach for temperature data collection. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 44 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.7.3. A7HEX + ssssHEX single temperature measurement for which the configuration register (Gain, ADC, Offset, etc.) will be loaded as the user’s configuration ssssHEX, which must be provided externally via the interface as the data part of this command. The format and purpose of these configuration bits must be according to the definitions for SM_config and valid for temperature measurement in this case (bits [15:13] will be ignored). Calibration Step 3a) – Coefficient Calculations The math to perform the coefficient calculation is complicated and will not be discussed in detail. There is a brief overview in the next section. ZMDI provides software (DLLs) to perform the coefficient calculation (external to the sensor-ZSSC3218 system) based on auto-zero corrected values. After the coefficients are calculated, the final step is to write them to the MTP memory of the ZSSC3218. 3.7.4. Calibration Step 3b) – Post-Calibration Offset Correction There are two special SSC coefficients, SENS_shift and T_shift. Normally, these coefficients must be predetermined as zero during the initial sensor calibration. The primary purpose of these two coefficients is to cancel additional offset shifts that could occur during or after final sensor assembly; e.g. if a respective sensor is finally placed and soldered on an application board. If the final sensor assembly induced any kind of offset (on either the temperature or external sensor signal), the respective influence can be directly compensated by means of the SENS_shift and T_shift coefficients without the need to change the original SSC coefficient set. However, this post-calibration offset correction must be done under known ambient conditions (i.e., sensor measurand and/or temperature). 3.7.5. SSC Measurements After the completion of the calibration procedure, linearized external sensor and temperature readings can be obtained using the commands AAHEX to AFHEX as described in Table 3.1. Typically, only one external sensor is used in a single analog configuration using the setup in the SM_config1 MTP register (12HEX). However, the ZSSC3218 can support a second analog configuration that is set up in the SM_config2 MTP register (16HEX). This might be useful in cases where only one sensor-ZSSC3218 pair must support the measurand ranges for two different external sensors that have different precisions, required amplification, and sensor offset. If a respective switching between setups is to be performed, the SSC coefficients for the alternate external sensor must be handled with one of the following methods: The programmed SSC coefficients are not used for the alternate external sensor. The ZSSC3218 performs only a factor-one transfer, i.e. no effective digital SSC correction – only a transfer of the auto-zero corrected raw ADC readings to the ZSSC3218 output without any scaling, etc. The coefficients are re-programmed each time the analog setup is changed. SM_config1 is selected as the analog setup register by default, so no specific activation is needed if only SM_config1 is used. If SM_config2 will also be used, the activation command B1HEX must be sent once prior to the measurement request. To switch to using SM_config1, the activation command B0HEX must be sent prior to use. This respective activation must be refreshed after any power-on-reset or RES pin reset. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 45 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.8. The Calibration Math 3.8.1. Bridge Signal Compensation The saturation check in the ZSSC3218 detects saturation effects of the internal calculation steps, allowing the final correction output to be determined despite the saturation. It is possible to get potentially useful signal conditioning results that have had an intermediate saturation during the calculations. These cases are detectable by observing the status bit[0] for each measurement result. Details about the saturation limits and the valid ranges for values are provided in the following equations. The calibration math description assumes a calculation with integer numbers. The description is numerically correct concerning values, dynamic range, and resolution. SOT_curve selects whether second-order equations compensate for sensor nonlinearity with a parabolic or S-shaped curve. The parabolic compensation is recommended for most sensor types. For the following equations, the terms are as follows: 2 S = Corrected sensor reading output via I C™ or SPI; range [0HEX to FFFFFFHEX] S_Raw = Raw sensor reading from ADC after AZ correction; range [-0x7FFFF, 0x7FFFF] Gain_S = Sensor gain term; range [-0x7FFFF, 0x7FFFF] Offset_S = Sensor offset term; range [-0x7FFFF, 0x7FFFF] Tcg = Temperature coefficient gain term; range [-0x7FFFF, 0x7FFFF] Tco = Temperature coefficient offset term; range [-0x7FFFF, 0x7FFFF] T_Raw = Raw temperature reading after AZ correction; range [-0x7FFFF, 0x7FFFF] SOT_tcg = Second-order term for Tcg non-linearity; range [-0x7FFFF, 0x7FFFF] SOT_tco = Second-order term for Tco non-linearity; range [-0x7FFFF, 0x7FFFF] SOT_sens = Second-order term for sensor non-linearity; range [-0x7FFFF, 0x7FFFF] SENS_shift = post-calibration, post-assembly sensor offset shift; range [-0x7FFFF, 0x7FFFF] = absolute value ulll = bound/saturation number range from ll to ul, over/under-flow is reported as saturation in the status byte Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 46 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC The correction formula for the differential signal reading is represented as a two-step process depending on the SOT_curve setting. Equations for the parabolic SOT_curve setting (SOT_curve = 0): Simplified: K1 2 23 T _ Raw 4 SOT _ tcg T _ Raw 4 Tcg 23 23 2 2 K 2 4 Offset_ S S _ Raw Z SP S T _ Raw 4 SOT _ tco T _ Raw 4 Tco 23 23 2 2 4 Gain _ S K1 23 K 2 2 23 2 23 2 Z BP 4 SOT _ sens Z SP 223 SENS _ shift 223 223 Data Sheet November 17, 2014. (delimited to positive number range) (delimited to positive number range) © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. (1) (2) (3) (4) 47 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Complete: 2 25 1 2 1 2 25 1 2 25 1 23 T _ Raw SOT _ tcg K 1 2 T _ Raw 4Tcg 23 21 2 225 2 225 25 2 25 2 25 (5) 2 25 1 2 1 2 25 1 2 25 1 25 2 1 T _ Raw SOT _ tco K 2 4 Offset _ S S _ Raw T _ Raw 4Tco 21 2 23 225 2 225 25 2 225 25 2 25 Z SP Gain _ S 2 21 225 1 K 231 K 2 2 225 2 1 23 2 225 25 (6) 225 1 (7) 0 224 1 2 1 225 1 Z SP SOT _ sens 23 B 23 Z BP 2 SENS _ shift 2 2 21 25 2 225 0 25 (8) Equations for the S-shaped SOT_curve setting (SOT_curve = 1): Simplified: Z SS S 4 Gain _ S K1 23 K 2 2 23 2 (9) Z SS 4 SOT _ sens Z SS 2 23 2 23 SENS _ shift 23 23 2 2 (delimited to positive number range) (10) Complete: Z SS Gain _ S 21 2 Z SS S 23 2 225 1 K 231 K 2 2 225 225 1 225 (11) 2 25 1 2 1 SOT _ sens Z 2 23 SS 21 2 25 2 25 2 Data Sheet November 17, 2014. 25 2 25 1 2 25 2 24 1 23 2 SENS _ shift 0 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. (12) 48 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.8.2. Temperature Signal Compensation Temperature is measured internally. Temperature correction contains both linear gain and offset terms as well as a second-order term to correct for any nonlinearities. For temperature, second-order compensation for nonlinearity is always parabolic. The correction formula is best represented as a two-step process as follows: Simplified: ZT 4 Gain _ T T _ Raw 4 Offset _ T 2 23 (delimited to positive number range) 2 23 (13) T Z T 4 SOT _ T Z T 2 23 T _ Shift 23 23 2 2 (14) (delimited to positive number range) Complete: 2 25 1 2 1 Gain _ T 2 25 1 Z T T _ Raw 4 Offset _ T 2 23 25 2 21 225 2 0 25 (15) 2 24 1 2 1 2 25 1 SOT _ T Z 23 T T 23 21 Z T 2 T _ Shift 2 2 25 2 225 0 25 (16) Where 2 T = Corrected temperature sensor reading output via I C™ or SPI; range [0HEX to FFFFFFHEX] Gain_T = Gain coefficient for temperature; range [-7FFFFFHEX to 7FFFFFHEX] T_Raw = Raw temperature reading after AZ correction; range [-7FFFFFHEX to 7FFFFFHEX] Offset_T = Offset coefficient for temperature; range [-7FFFFFHEX to 7FFFFFHEX] SOT_T = Second-order term for temperature source non-linearity; range [-7FFFFFHEX to 7FFFFFHEX] T_Shift = Shift for post-calibration/post-assembly offset compensation; range [-7FFFFFHEX to 7FFFFFHEX] Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 49 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 3.8.3. Measurement Output Data Format The data format and bit assignment of the raw measurement and SSC-corrected outputs of the ZSSC3218 are defined in the following tables. Any ADC measurement and SSC calculation output is formatted as a 24-bit wide data word, regardless of the effective ADC resolution used. The values are either in two’s complement or signabsolute format. Table 3.6 Measurement Results of ADC Raw Measurement Request (two’s complement) Bit 23 Meaning, Weighting -2 Table 3.7 0 22 2 -1 23 22 Meaning, weighting 0=positive 1=negative 2 -2 … -3 … 2 1 2 0 -22 2 -23 1 21 2 0 20 … -1 … 2 1 2 0 -20 2 -21 Output Results from SSC-Correction Math or DSP—Sensor and Temperature Bit 23 Meaning, weighting 2 Table 3.9 2 20 Calibration Coefficients (Factors and Summands) in Memory (sign-magnitude) Bit Table 3.8 21 0 22 2 -1 21 2 -2 20 … -3 … 2 1 2 0 -21 2 -23 Interrupt Thresholds TRSH1 and TRSH2—Format as for SSC-Correction Math Output Bit 23 Meaning, weighting 2 Data Sheet November 17, 2014. 0 22 2 -1 21 2 -2 20 … -3 … 2 1 2 -21 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 0 2 -23 50 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 4 Package Information and Pad Assignments The ZSSC3218 is available in die form or as engineering samples in the PQFN24 package. See Figure 4.1 for additional die dimensions. In Figure 4.1, the outer dimensions shown are (minimum) estimations for a die after sawing without remaining scribe-line silicon around the core die. Therefore, the effective outer dimensions might differ slightly. Figure 4.1 ZSSC3218 Pad Placement Seal Ring IC Core VDD ZMDI-test VSS ZMDI-test ZMDI-test RES VDDB INN SS ZMDI-test INP VSSB EOC MOSI/SDA MISO ZMDI-test Data Sheet November 17, 2014. SCLK/SCL © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 51 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Table 4.1 Pad Assignments Name Direction Type VDD IN Supply IC positive supply voltage for the IC. VSS IN Supply Ground reference voltage signal. RES IN Digital IC reset (low active, internal pull-up). VDDB OUT Analog Positive external bridge-sensor supply. INN IN Analog Negative sensor signal (or sensor-ground for absolute voltagesources sensors). EOC OUT Digital End of conversion or interrupt output. MISO OUT Digital Data output for SPI. SS IN Digital Slave select for SPI. INP IN Analog Positive sensor signal. VSSB OUT Analog Negative external bridge-sensor supply (sensor ground). MOSI/SDA IN/Out Digital Data input for SPI; data in/out for I²C™. SCLK/SCL IN Digital Clock input for I²C™/SPI. ZMDI-test - - Table 4.2 Description Do not connect to these pads. Die Connection and Bond Parameter Parameter Au Bond, Pull-Force TYP MAX - 8g Cu Bond, Pull-Force Contact Push-Force to Pad Probing Overdrive not specified 0.05g/µm 0.1g/µm - 55µm Description / Notes Soft bonding recommended. Strongly not recommended. Applied force during wafer sort and/or bond-wire connection. Up to 4 touch downs at 85°C maximum; cantilever probe. Generally, it is strongly recommended that bond and connection experiments be conducted in order to determine a proper assembly setup (golden wire, time, power, bonding force, etc. by means of wire-pull test, ball-shear test, and others) that does not lead to any IC and/or pad damages. Higher bond pull-forces maybe possible depending directly on the bond tool and temperature. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 52 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Figure 4.2 General PQFN24 Package Dimensions Table 4.3 Physical Package Dimensions Parameter / Dimension Min (mm) Max (mm) A 0.80 0.90 A1 0.00 0.05 b 0.18 0.30 e 0.5nom HD 3.90 4.10 HE 3.90 4.10 L 0.35 0.45 Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 53 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC Table 4.4 Pin Assignments PQFN24 Pin No. Name 1) Direction Type Description 1 ZMDI-test - - 2 RES IN Digital IC reset (low active, internal pull-up). 3 VDDB OUT Analog Positive external bridge-sensor supply. 4 INN IN Analog Negative sensor signal (or sensor ground for absolute voltage-source sensors). 5 EOC OUT Digital End of conversion or interrupt output. 6 MISO OUT Digital Data output for SPI. 7 ZMDI-test - - Do not connect. 8 n.c. - - - 9 n.c. - - - 10 n.c. - - - 11 n.c. - - - 12 SCLK/SCL IN Digital Clock input for I²C™/SPI. 13 MOSI/SDA IN/Out Digital Data input for SPI; data in/out for I²C™. 14 VSSB OUT Analog Negative external bridge-sensor supply (sensor ground). 15 INP IN Analog Positive sensor signal. 16 ZMDI-test - - 17 SS IN Digital 18 ZMDI-test - - Do not connect. 19 ZMDI-test - - Do not connect. 20 n.c. - - - 21 n.c. - - - 22 VDD IN Supply 23 n.c. - - 24 VSS IN Supply 25 Exposed Pad - - 1) Do not connect. Do not connect. Slave select for SPI IC positive supply voltage for the ZSSC3218. Ground reference voltage signal. Do not connect electrically. n.c. stands for not connected / no connection required / not bonded. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 54 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 5 Quality and Reliability The ZSSC3218 is available as a qualified IC for consumer-market applications. All data specified parameters are guaranteed if not stated otherwise. 6 Ordering Sales Codes Sales Code Description Package ZSSC3218BI1B Die—temperature range: –40°C to +85 °C, thickness 304µm Unsawn wafer ZSSC3218BI2B Die—temperature range: –40°C to +85 °C, thickness 725µm (w/o backlapping) Unsawn wafer ZSSC3218BI1D ES Die—temperature range: –40°C to +85 °C, thickness 304µm, engineering samples Sawn die in waffle pack ZSSC3218BI3R ES PQFN24—temperature range: –40°C to +85 °C, engineering samples Packaged die Contact ZMDI Sales for additional information. 7 Related Documents Note: X_xy refers to the current revision of the document. Document File Name ZSSC3218 Feature Sheet ZSSC3218_Feature_Sheet_Rev_X_xy.pdf Visit the ZSSC3218 product page www.zmdi.com/zssc3218 on ZMDI’s website www.zmdi.com or contact your nearest sales office for ordering information or the latest version of these documents. Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 55 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 8 Glossary Term Description A2D Analog-to-Digital ACK Acknowledge (interface’s protocol indicator for successful data/command transfer) ADC Analog-to-Digital Converter or Conversion ALU Arithmetic Logic Unit AZ Auto-Zero (unspecific) AZSM Auto-Zero Measurement for (external) Sensor Path AZTM Auto-Zero Measurement for Temperature Path Au Gold CLK Clock Cu Copper DAC Digital-to-Analog Conversion or Converter DF Data Fetch (command type) DSP Digital Signal Processor EOC End of Conversion FSO Full Scale Output (value in percent relative to the ADC maximum output code; resolution dependent) LSB Least Significant Bit LFSR Linear Feedback Shift Register MR Measurement Request (command type) MSB Most Significant Bit MTP Multiple-Time Programmable Memory NACK Not Acknowledge (interface’s protocol indicator for unsuccessful data/command transfer) POR Power-on Reset PreAmp Preamplifier PSRR Power Supply Disturbance Rejection Ratio SM Signal Measurement SOT Second-Order Term TC Temperature Coefficient (of a resistor or the equivalent bridge resistance) TM Temperature Measurement Data Sheet November 17, 2014. © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 56 of 57 ZSSC3218 High-End 18-Bit Sensor Signal Conditioner IC 9 Document Revision History Revision Date Description 1.00 August 21, 2014 First release. 1.01 September 11, 2014 Update for Sleep State current on page 2. Minor edits. 1.02 October 2, 2014 Update of SSC-noise values in Table 2.6. 1.03 November 17, 2014 Corrections in Table 3.5 for settings for CYC_period, Gain_stage1, Gain_stage2, Adc_bits and Offset. Correction for Figure 2.3. Sales and Further Information www.zmdi.com [email protected] Zentrum Mikroelektronik Dresden AG Global Headquarters Grenzstrasse 28 01109 Dresden, Germany ZMD America, Inc. 1525 McCarthy Blvd., #212 Milpitas, CA 95035-7453 USA Central Office: Phone +49.351.8822.306 Fax +49.351.8822.337 USA Phone 1.855.275.9634 Phone +1.408.883.6310 Fax +1.408.883.6358 European Technical Support Phone +49.351.8822.7.772 Fax +49.351.8822.87.772 DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer, licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or otherwise. European Sales (Stuttgart) Phone +49.711.674517.55 Fax +49.711.674517.87955 Data Sheet November 17, 2014. Zentrum Mikroelektronik Dresden AG, Japan Office 2nd Floor, Shinbashi Tokyu Bldg. 4-21-3, Shinbashi, Minato-ku Tokyo, 105-0004 Japan ZMD FAR EAST, Ltd. 3F, No. 51, Sec. 2, Keelung Road 11052 Taipei Taiwan Phone +81.3.6895.7410 Fax +81.3.6895.7301 Phone +886.2.2377.8189 Fax +886.2.2377.8199 Zentrum Mikroelektronik Dresden AG, Korea Office U-space 1 Building 11th Floor, Unit JA-1102 670 Sampyeong-dong Bundang-gu, Seongnam-si Gyeonggi-do, 463-400 Korea Phone +82.31.950.7679 Fax +82.504.841.3026 © 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice. 57 of 57